diff --git a/src/api/mod.rs b/src/api/mod.rs
index dc27492..8b4a76c 100644
--- a/src/api/mod.rs
+++ b/src/api/mod.rs
@@ -23,7 +23,8 @@ pub fn api_router() -> Router {
         .route("/api/users/me", get(users::get_me))
         .route("/api/users/{id}", get(users::get_by_id))
         .route("/api/users/@{handle}", get(users::get_by_handle))
-        .route("/api/users/{id}/setpassw", get(users::change_password))
+        .route("/api/users/{id}/setpassw", post(users::change_password))
+        .route("/api/users/{id}/sethandle", post(users::change_handle))
         .route("/api/sessions/{id}", get(sessions::get_by_id))
         .route("/api/sessions/{id}/revoke", post(sessions::revoke_by_id))
         .route("/api/tags/{id}", get(tags::get_by_id))
diff --git a/src/api/users.rs b/src/api/users.rs
index 1ae2ebf..a1b9ef4 100644
--- a/src/api/users.rs
+++ b/src/api/users.rs
@@ -17,7 +17,9 @@ use crate::{
     },
 };
 
+const CANT_CHANGE_OTHERS_HANDLE: &str = "You don't have permission to change this user's handle.";
 const CANT_CHANGE_OTHERS_PASSW: &str = "You don't have permission to change this user's password.";
+const HANDLE_CHANGED_SUCCESS: &str = "Handle changed successfully.";
 const PASSW_CHANGED_SUCCESS: &str = "Password changed successfully.";
 
 pub async fn get_me(headers: HeaderMap) -> Result<Response, CompositeError> {
@@ -40,6 +42,28 @@ pub async fn get_by_handle(
     Ok(Json(User::get_by_handle(handle)?).into_response())
 }
 
+#[derive(Deserialize)]
+pub struct ChangeHandleForm {
+    handle: UserHandle,
+}
+pub async fn change_handle(
+    Path(id): Path<Uuid>,
+    headers: HeaderMap,
+    Json(form): Json<ChangeHandleForm>,
+) -> Result<Response, CompositeError> {
+    let u = User::authenticate(&headers)?.required()?;
+    let mut target = if u.id == id {
+        u
+    } else {
+        if u.has_permission(Permission::ChangeOthersHandles)? == false {
+            return Ok((StatusCode::FORBIDDEN, CANT_CHANGE_OTHERS_HANDLE).into_response());
+        }
+        User::get_by_id(id)?
+    };
+    target.set_handle(form.handle)?;
+    Ok(HANDLE_CHANGED_SUCCESS.into_response())
+}
+
 #[derive(Deserialize)]
 pub struct ChangePasswordForm {
     password: String,
diff --git a/src/users/mod.rs b/src/users/mod.rs
index f562bc6..942b122 100644
--- a/src/users/mod.rs
+++ b/src/users/mod.rs
@@ -2,7 +2,7 @@ use axum::{
     http::StatusCode,
     response::{IntoResponse, Response},
 };
-use rusqlite::OptionalExtension;
+use rusqlite::{ErrorCode, OptionalExtension};
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
 
@@ -35,6 +35,8 @@ pub enum UserError {
     NoUserWithId(Uuid),
     #[error("No user found with handle {0}")]
     NoUserWithHandle(UserHandle),
+    #[error("A user with handle {0} already exists")]
+    HandleAlreadyExists(UserHandle),
     #[error("Database error: {0}")]
     DatabaseError(String),
     #[error("Argon2 passhash error: {0}")]
@@ -72,6 +74,21 @@ impl User {
             None => Err(UserError::NoUserWithHandle(handle)),
         }
     }
+    pub fn set_handle(&mut self, new_handle: UserHandle) -> Result<(), UserError> {
+        let conn = database::conn()?;
+        conn.prepare("UPDATE users SET handle = ?1 WHERE id = ?2")?
+            .execute((&new_handle, self.id))
+            .map_err(|e| {
+                if let Some(e) = e.sqlite_error() {
+                    if e.code == ErrorCode::ConstraintViolation {
+                        return UserError::HandleAlreadyExists(new_handle.clone());
+                    }
+                }
+                UserError::from(e)
+            })?;
+        self.handle = new_handle;
+        Ok(())
+    }
 }
 
 // DANGEROUS: AUTH
@@ -123,7 +140,6 @@ impl User {
     /// to do everything and probably should not be used as a regular account
     /// due to the ramifications of compromise. But it could be used for that,
     /// and have its name changed.
-    #[allow(unused)]
     pub fn is_infradmin(&self) -> bool {
         self.id == Uuid::max()
     }
@@ -169,7 +185,6 @@ impl User {
     /// for actions performed by Mnemosyne internally.
     /// It shall not be available for log-in.
     /// It should not have its name changed, and should be protected from that.
-    #[allow(unused)]
     pub fn is_systemuser(&self) -> bool {
         self.id == Uuid::nil()
     }
@@ -199,6 +214,7 @@ impl IntoResponse for UserError {
             Self::UserHandleError(_) => (StatusCode::BAD_REQUEST, self.to_string()),
             Self::NoUserWithId(_) => (StatusCode::BAD_REQUEST, self.to_string()),
             Self::NoUserWithHandle(_) => (StatusCode::BAD_REQUEST, self.to_string()),
+            Self::HandleAlreadyExists(_) => (StatusCode::CONFLICT, self.to_string()),
         }
         .into_response()
     }
diff --git a/src/users/permissions.rs b/src/users/permissions.rs
index 73dc146..d87ae31 100644
--- a/src/users/permissions.rs
+++ b/src/users/permissions.rs
@@ -8,10 +8,13 @@ pub enum Permission {
     RevokeOthersSessions,
     // All Users have the right to change their own password
     ChangeOthersPasswords,
+    // All Users have the right to change their own handle
+    ChangeOthersHandles,
 }
 
 impl User {
     pub fn has_permission(&self, permission: Permission) -> Result<bool, DatabaseError> {
+        // Infradmin and systemuser have all permissions
         if self.is_infradmin() || self.is_systemuser() {
             return Ok(true);
         }
diff --git a/src/users/sessions.rs b/src/users/sessions.rs
index bf113b1..142ea4c 100644
--- a/src/users/sessions.rs
+++ b/src/users/sessions.rs
@@ -139,7 +139,6 @@ impl Session {
         Ok(())
     }
 
-    #[allow(unused)]
     pub fn revoke(&mut self, actor: Option<&User>) -> Result<(), SessionError> {
         let now = Utc::now();
         let id = actor.map(|u| u.id).unwrap_or(Uuid::nil());